Texturing - Triplanar and Bump

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Hi all,

ok .. houdini is my first 3d package, and i do a lot of tutorials designed for other software and general techniques, applying it to Houdini.
This is mainly because there are tons of tutorials for lots of cool modelling and texturing techniques that i use to learn the fundamentals.

Houdini lets me take it a stage further and really learn 3d by understanding whats going on where…which is cool…but..

…to get to my question, unless im mistaken, why is there no bump map option for the vex layered shader? I've made my own shaders in vops, using bump maps when needed, which i love doing…but the vex layered is so cool i just find it bizarre that bump mapping is not available - to have to make a massive multi-layered shader in Vops just to have bump seems crazy when u have such a cool shader already available. Same for the super material!

Also, is there anything in Houdini that is the equivalent of Triplanar mapping in other brands? A lot of tutorials use this technique, and i cant seem to find a way of doing something similar.

Cheers y'all

J
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About the Triplanar Mapping thing. I looked it up on google and from what I've seen UVUnwrap seems to do exactly that.

http://www.newcottage.com/index.php?section=lab&subsection=lab/uv2 [newcottage.com]

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thanks Dajuice - much appreciated!

J
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As for bump maps, my attitude these days is why even bother? Unless I can be convinced otherwise.

Both Mantra and RenderMan are fantastic at displacements with no real costs in terms of speed hits. Micropolygon dicing and displacements rule in this area.

The only management from the user side is to make sure you have set the Displace Bounds value correctly to hint at Mantra and RenderMan to “make a little extra room” for the geoemtry when rendering so as to not get those nasty holes or tears in the render.

Oh and one other gotcha for objects with displacements close to a camera. The displacements may actually push the geometry through the camera lens causing an eyesplits problem. Watch out for that.

Bump mapping is fun up to a point but displacements are the real deal.
There's at least one school like the old school!
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Hi Jeff

- thats a fair point, however i actually prefer to combine bump and disp - using bump for finer detail when using displacement more usefully for larger features.

my point about the Layed shader was that it has the ability to use different UV spaces, and combine images in a really neat way. It would be helpful for cg artists to also have bump there as an option in my opinion.

HoweverI agree in that displacement has its place over bump wherever possible - so is there a specific way to layer disp maps to correspond with the exact uv settings of the Vex Layered?

cheers

J
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agreed displacements are really nice, but is it me or does using displacements with GI increase render times quite a lot? is that just because the displacement is calculated before the GI therefore the models are more complex?
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Yeah, I think bumps have their place. I only go to displacement when I have to(which admittedly is often). Depends on what you're trying to do.

Cheers,

J.C.
John Coldrick
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just be warned to keep your normals sound when mixing bump and displacements.

bumpMaps are so late 70s
-k
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There are so many occasions in shots where bump mapping saves headaches and time. I suppose the biggest thing is that you dont have to worry about the displacement being phycially correct in 3d space so it does not intersect or implode. It renders without errors even when you crank it way up. The last and best reason to use bump map is that it lets you paint sloppy disp maps when you are in rush.

However there are just as many reasons to use displacements. It really depends on the shot.
soho vfx
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I take it then that bumps are still “in” so the RFE to add support for bump maps in many of the default SHOPs is valid.


-jeff
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I take it then that bumps are still “in” so the RFE to add support for bump maps in many of the default SHOPs is valid.

Sweet - cheers Jeff!

bumpMaps are so late 70s

LOL! like so many great things eh?!
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the UV unwrap has nothing todo with Tri-planar projections…
Tri-planaer works without any UV's
http://therenderblog.com/altriplanar-node-for-maya/ [therenderblog.com]
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That is not true, everything has to do with UVs.
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triplanar in maya
TriPlanar: Projects the texture by extruding it along the axis defined by the maximum current direction of the surface normal. This is somewhat like fabric being wrapped around the object.
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Here is a working example of a triplanar projection setup in mantra

Attachments:
tri_planar_setup.hip (274.8 KB)

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